Method and apparatus for controlling the reproduction of data stored on a storage medium method

ABSTRACT

Plural program information and a BCA (Burst Cutting Area) number of the optical disc (100) is previously recorded in the optical disc (100). A drive ID is stored in the nonvolatile memory (104a) of the reproduction apparatus (104). A user of the reproduction appparatus (104) notifies the BCA number, the drive ID, and a number of preferred program information to the software house (software supplier(110) on the condition that the user pays for the reproduction of the preferred program information recorded in the optical disc (100). The software house (110) notifies a cipher key to the reproduction apparatus (104) or the user. A title key is calculated in the reproduction apparatus (104) in accordance with the BCA number, the drive ID, and the cipher key. The preferred information recorded in the optical disc (100) is permitted to be reproduced by using the title key.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a managing system of permittingreproduction of program information when the program information to bereproduced is recorded in an optical disc such as a CD (Compact Disc) ora DVD (Digital Video Disc or Digital Versatile Disc), particularly, andrelates to improvements in a cipher key producing method, a cipher keywriting method, a cipher key reproduction apparatus, an informationreproduction method, an information reproduction permitting method, anda reproduction apparatus of optical disc so as to protect an opticaldisc from illegal utilization thereof and illegal duplication or copytherefrom.

2. Description of the Related Art

In an optical disc package media such as a CD, all program informationcontained in an optical disc is disclosed to an owner of the disc, thatis, an owner of an optical disc can utilize all program informationcontained in the disc when the owner possesses the disc. As shown inFIG. 1, a software supplier (software house) 28 supplies an optical disc11 as indicated by an arrow 15 and collects a fee for the sold opticaldisc 11 by indicated by an arrow 16. A price of the optical disc 11 isfixed for total program information which is contained in the disc 11. Aconsumer pays a fixed price for the optical disc 11 in the currentdistribution system 10, that is, a consumer pays a fixed price for a"possession" of the program information which is contained in theoptical disc 11.

Generally, a price of the optical disc 11 is determined primarily forquality and quantity of program information contained in the disc 11,since the optical disc 11 without its program content can bemanufactured at an extremely low cost. In a distribution system 10, aconsumer is obliged to pay a total cost of the program informationcontained in the optical disc 11 although not all of such programinformation are wanted by the consumer. In other words, manufacturers ofoptical discs are obliged to manufacture wide variety of optical discsin their contents to meet a wide variety of demands by consumers. Thiscauses a price boost of each of such discs. On the other hand, asconsumers prefer to purchase optical discs at lower prices, the abovesituation invites illegally duplicated optical discs sold at very lowprices into the market. The above mentioned distribution system 10 isnot only unfavorable to the consumers but also increases cost andcomplexity of distribution for manufacturers and software houses.

In contrast with the above mentioned distribution system 10, a "superdistribution system" 20 is known. The "super distribution system" 20 isa system of paying for a "utilization" of the program information notfor a "possession" of program information. According to the "superdistribution system" 20, a consumer just pays for a utilized programinformation. The unfavorable deal in the above mentioned distributionsystem 10 of paying for a "possession" of program information isdissolved by the "super distribution system" 20 and it is supposed to bea more rational system. In the "super distribution system" 20, autilization state of program information and information of limitationof the utilization are transmitted to a managing system through acommunication network.

As shown in FIG. 1, an optical disc 21 is supplied at a low price by asoftware house 28 a shown by an arrow 25, wherein program informationrecorded in the optical disc 21 is coded so as to comply with the "superdistribution system". An optical disc player 22 which reproduces programinformation (software) recorded in the optical disc 21 is equipped witha connector 24 for an IC card and a communication port 23 for atelephone line. Data of credited amount for reproduction is prestored inthe IC card and the data is renewed at each time when reproducing theprogram information so as to deduct the credited amount. Thecommunication port 23 is connected to a host computer of a softwarehouse 28 through a telephone line wherein reproduction fees of opticaldiscs are collected as indicated by an arrow 26 and a revised creditedamount responsive to the reproduction is newly set as indicated by anarrow 27. A software house 28 includes dealers such as retailers andcredit card issuing companies.

FIG. 2 shows an example of a "super distribution system". The example isapplied to game software. For example, an optical disc 900 recorded witha game software is supplied together with an extra software of amagazine 902 to game players. In other words, a user of the gamesoftware obtains the optical disc 900 by purchasing the magazine 902 asindicated by an arrow 911.

An inherent ID (identification) which identifies individual opticaldiscs is recorded on the optical disc 900. To record the inherent ID onprerecorded optical discs individually, the U.S. Pat. No. 5,400,319discloses a method of recording information of less recording densitythan the recording density of main information (essential information ofan optical disc) on an information recording surface of an optical discafter the optical disc is manufactured. Recording information in arecording area of low packing density is realized by permanentlydeforming a reflective membrane of a substrate of the optical disc byirradiating a strong laser beam. A typical linear recording density ofsuch a low density information is from 1/10 to 1/1000 of the recordingdensity of main information, preferably an extent of from 1/40 to 1/400.

A personal computer (or player) 904 which reproduces the optical disc900 is provided with a connector and a communication port, whereto an ICcard 906 and a modem 908 are connected. Data of credited amount forreproducing a game software is prestored in the IC card 906 and the datais renewed at the time upon reproducing the game software so as todeduct the credited amount. The modem 908 is connected to a managementcomputer 910 of a supplier (software house) of the game software througha communication line. In the management computer 910, credited amount isset and reproduction fees are collected.

A user loads the optical disc 900 on the personal computer 904. Thepersonal computer 904 transmits the following information (1) through(4) to the management computer 910 as indicated by an arrow 912: (1) anID of the optical disc 900 and a drive number of a drive unit whichreproduces the optical disc 900, (2) an ID of the game software to bereproduced, (3) an ID of the personal computer 904 as a reproductiondevice, and (4) an ID of the IC card 906. In the management computer910, a cipher key (or cipher number) is produced by combining thereceived information and then the cipher key is transmitted to thepersonal computer 904 as indicated by an arrow 913. Simplest example isexplained as follows with assumption of that the ID of the optical discis "123", the drive number is "122", the ID (title key) of the gamesoftware to be reproduced is "666", and the cipher key is "421". Themanagement computer 910 adds "123" of the optical disc ID, "122" of thedrive number both entered by the user, and "421" of the cipher keytogether. A sum becomes "666" (123+122+421=666). The number "666" is thetitle key to be reproduced, then the personal computer 904 reproducesthe game software of the title key "666".

Accordingly, before reproducing an optical disc, a user contacts firstwith a software house to obtain a cipher key which is necessary toutilize program information to be reproduced. Then the user canreproduce the program information by utilizing the cipher key. Onesoftware which is related to the cipher key out of several gamesoftwares contained in one optical disc 900 is reproduced. A cost forutilizing the program information is deducted from an amount of moneywhich is prestored in the IC card 906. The user can enjoy a gamesoftware within the credited amount of the IC card 906.

Moreover, in the "super distribution system", program informationrecorded in an optical disc can not be utilized without a cipher keyalthough an optical disc is available, therefore optical discs areprevented from illegal duplication. Since a cipher key is produced inconjunction with the inherent ID of an optical disc, a cipher key can beprepared for individual optical discs, that is, one cipher key can beutilized for just one optical disc. Therefore, it is impossible toutilize one cipher key for various optical discs or for several users.

According to the above mentioned "super distribution system", differentcipher keys are prepared for individual optical discs, therefore a useris obliged to manage the cipher keys. Especially, in the case ofpossessing many optical discs, a user is obliged to enter a differentcipher key for a different optical disc whenever reproducing an opticaldisc. The "super distribution system" is very convenient for a softwarehouse so that security for illegal utilization and illegal duplicationis enhanced. On the other hand, a cipher key varies by programinformation, so that managing various cipher keys is rather difficultfor a user.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a cipherkey producing method suitable for easy management of the cipher key inconjunction with preventing from illegal utilization or duplication ofprogram information.

In order to achieve the above object, the present invention provides,according to an aspect thereof, a cipher key producing method wherein acipher key is produced by both of or one of ID information whichdiscriminate one optical disc from other optical discs and a drive IDwhich discriminates one reproduction apparatus for an optical disc fromother reproduction apparatuses in conjunction with a specificinformation which specifies at least one preferred program informationto be reproduced out of plural program information recorded in oneoptical disc. A cipher key is produced for respective programinformation which are requested to be reproduced or for respectivegroups of plural program information which are requested to bereproduced.

According to the aspect of the present invention, a cipher key writingmethod and writing apparatus is provided. A cipher key is additionallywritten in an area which is continued to or adjacent to an area whereinessential program information of an optical disc is recorded.

According to another aspect of the present invention, a reproductionpermitting method is provided. Program information which are recorded inan optical disc is permitted to reproduce when a appropriate cipher keyis applied.

In more specific aspect of the present invention, there provided areproduction method and a reproduction apparatus which reproduces anoptical disc written with a cipher key.

Other objects and further features of the present invention will beapparent from the following detailed description with respect topreferred embodiments of the invention when read in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a concept of software supplying system operated between auser and a software supplier (software house) of the prior art.

FIG. 2 shows an example of a "super distribution system" of the priorart.

FIG. 3 shows a cipher key producing method, reproducing method of anoptical disc, a reproduction apparatus of an optical disc, and apermitting system of reproducing an optical disc according to a firstembodiment of the present invention.

FIG. 4 shows a flow chart of process in a reproduction apparatus ofoptical disc shown in FIG. 3.

FIG. 5 shows a flow chart of process in a software house shown in FIG.3.

FIG. 6 shows a flow chart of transmission process of information in areproduction apparatus of optical disc shown in FIG. 3 according to asecond embodiment of the present invention.

FIG. 7 shows a flow chart of receiving process of a cipher key andwriting process of a cipher key to an optical disc in a reproductionapparatus of optical disc shown in FIG. 3 according to the secondembodiment of the present invention.

FIG. 8 shows a flow chart of permitting or prohibiting reproductionprocess in a reproduction apparatus of optical disc shown in FIG. 3according to the second embodiment of the present invention.

FIG. 9 shows another flow chart of permitting or prohibitingreproduction process in a reproduction apparatus of optical disc shownin FIG. 3 according to the second embodiment of the present invention.

FIG. 10 shows a flow chart of producing and writing process of a cipherkey according to a third embodiment of the present invention.

FIG. 11 shows a flow chart of reproduction process of an optical discaccording to the third embodiment of the present invention.

FIG. 12 shows a block diagram of a reproduction apparatus of opticaldisc according to the third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[First Embodiment]

FIG. 3 shows a cipher key producing method, reproducing method of anoptical disc, a reproduction apparatus of optical disc, and a permittingsystem of reproducing an optical disc according to the first embodimentof the present invention.

FIG. 4 shows a flow chart of process in a reproduction apparatus ofoptical disc shown in FIG. 3.

FIG. 5 shows a flow chart of process in a software house shown in FIG.3.

In a first embodiment, the present invention provides a cipher keyproducing method wherein a cipher key is produced by both or one ofeither ID information which discriminate one optical disc from otheroptical discs and a drive ID which discriminates one reproductionapparatus of optical disc from other reproduction apparatuses of opticaldisc in conjunction with information which specifies at least oneprogram information to be reproduced out of plural program informationrecorded in one optical disc, and wherein a cipher key is produced forindividual program information which are requested to be reproduced orfor respective groups of plural program information to be reproduced.The present invention also provides a reproduction permitting methodwherein reproduction of program information is permitted only when acorrect cipher key is inputted.

A total distribution system of game software is shown in FIG. 3 as anexample, wherein an optical disc 100 recorded with a game software isreproduced by a reproduction apparatus 104 and a cost for reproductionis collected from a user of the reproduction apparatus 104 by a softwaresupplier (software house) 110 according to a first embodiment of thepresent invention.

According to the present invention, a reproducing system of an opticaldisc which is recorded with game software (program information) andtitle information (hereinafter called as a title key) is provided,wherein the title key is assigned to each game software. The title keyis read out from the optical disc to reproduce preferred programinformation.

In FIG. 3, the optical disc 100 is supplied to a user free of charge orat a low price, for example, as extra software of a magazine 102 asindicated by an arrow 111. In an information area of the optical disc100, several game softwares and an inherent information (hereinaftercalled as a disc ID) which discriminates the optical disc 100 from otherdiscs is recorded. Further, a title key is assigned to each gamesoftware or a group of game softwares. Furthermore, the title key isnumbered correspondingly to a sequential number of softwares one by oneaccording to the first embodiment of the present invention. It ispossible to correspond a title key to a file name of software instead.The software house 110 as an optical disc supplier and the reproductionapparatus 104 of a user side can communicate with each other through atelecommunication line, wherein a CPU (Central Processing Unit) an daninterface are equipped as well although they are not indicated in FIG.3.

In the optical disc 100, two units of address information of an area arerecorded, for instance, at a sector head. The one address information isfor a first scene of each software for example wherein reproduction ispermitted without a cipher key and the other one is for a main data areaof software wherein reproduction is prohibited unless a cipher key isentered. The reproduction apparatus 104 is arranged that it canreproduce a first scene of each software for example, however, it isimpossible to reproduce succeeding scenes of the software unless acipher key is entered.

To record the disc ID, binary data which represents the disc ID isrecorded on an optical disc 100 as a bar code, after recordinginformation of less packing density than recording density of the maininformation (essential information of an optical disc) on a surface ofthe optical disc 100, as the U.S. Pat. No. 5,400,319 discloses. A stronglaser beam which is modulated by binary data representing a disc ID isirradiated on an optical disc 100, as a result a reflective membrane ofa substrate of the optical disc 100 is permanently deformed at aposition of binary data "1" on the optical disc 100 wherein a disc ID isrecorded as a bar code such as "reflective =1" or "not reflective =0".In the first embodiment of the present invention, a BCA (Burst CuttingArea) number which is utilized in a DVD (Digital Video Disc) system isrecorded as a disc ID. The BCA area is an area extending over pluraltracks of inner most part of optically recorded area of an optical disc,wherein a bar code is formed by a strong light beam such as a YAG(yttrium aluminum garnet) laser beam, and wherein another bar code canbe written. The BCA number is a information proper to an individualoptical disc out of all information written in a BCA area as a bar code.The reproduction apparatus 104 reads out the BCA number and indicatesthe BCA number in decimal digit for instance. It is possible to providea recording area by other recording method than BCA number such asmagnetic recording area on an optical disc and a magnetic head providedexclusively for readout reads out information from the recording area.

In the reproduction apparatus 104, an inherent drive ID is stored in anonvolatile storage (memory) 104a or a ROM (Read-Only Memory) so as tobe able to electrically read out. A drive ID is indicated on a displayof the reproduction apparatus 104 whenever the reproduction apparatus104 is activated thus a user can obtain the drive ID. The drive ID, andthe above mentioned BCA number, and an individual information ID ofplural program information recorded in the optical disc 100 are utilizedas a code for producing a cipher key. Further, the drive ID isprerecorded in a memory 104a of a reproduction apparatus 104 when it ismanufactured. A software house 110 manages that which user possesses areproduction apparatus with a predetermined drive ID. The managingsystem will follow.

When an optical disc 100 is loaded, the reproduction apparatus 104reproduces aforementioned information of the disc 100 whereinreproduction is permitted without entering a cipher key and displaysprogram information. A user can recognize an outline or a first scene ofpreferred software to be reproduced. However, a cipher key of thesoftware is not known at this stage to the user. A method of obtainingthe cipher key will follow on an assumption that the software number tobe reproduced is "06" and the title key is "00666" wherein the softwarenumber and the title key is actually recorded in the optical disc.

The user or the reproduction apparatus 104 notifies followinginformation to the software house 110 by transmitting a PB (Push Button)signal (dial tone signal) through an analog telecommunication line witha modem or through an ISDN (Integrated Services Digital Network) line asindicated by an arrow 112.

(1) BCA number of the optical disc 100 in 5 digits: "00123" forinstance.

(2) Drive ID number of the reproduction apparatus 104 in 5 digits:"00122" for instance,

(3) Credit card number for payment for the playing fee, and

(4) Number of the software to be reproduced in 2 digits: "06".

The cipher key which permits its reproduction in this case is, forexample, defined as follows:

Cipher key =(equals) "Title key" -(minus) "BCA number" -(minus) "DriveID", that is, ##EQU1## The software house 110 notifies the cipher key"00421" to the user or the reproduction apparatus 104 through a modem ora voice answer back machine on the condition that the user pays for thesoftware number "06" of the optical disc 100 as indicated by an arrow113.

FIG. 4 is a process flow chart in the reproduction apparatus 104 whereina title key is produced by utilizing a cipher key which is producedthrough a communication with the software house 110 shown in FIG. 3. Atsteps S1 and S2, a disc ID and a drive ID are respectively read out.When a preferred software number and a credit card number are entered(step S3), all information are transmitted to the software house 110(step S4). When the transmission is completed (step S5), a cipher key isreceived from the software house 110 and the cipher key is inputted intothe reproduction apparatus 104 (step S6), then a title key is calculatedas follows in conjunction with the cipher key, and the BCA number whichis read out from the optical disc 100, the drive ID which is read outfrom the own memory 104a (step S7):

Title key =(equals) "Cipher key" +(plus) "BCA number" +(plus) "DriveID", that is, ##EQU2## The title key is checked whether it is correct ornot (step S8). In case that the title key is correct, reproduction ofthe software number "06" of the optical disc 100 which is correspondingto the title key "00666" is permitted (step S9). In the case ofincorrect, reproduction is prohibited (step S10).

FIG. 5 is a process flow chart in the software house 110. When thesoftware house 110 receives all the information from the user or thereproduction apparatus 104 (step S21), a cipher key is producedaccording to the aforementioned process (step S22) and the cipher key istransmitted to the user or the reproduction apparatus 104 (step S23).When the transmission is completed (step S24), necessary fee is chargedto the user's credit card account in accordance with the credit cardnumber which is received from the user in the step S21 (step S25) and atotal process in the software house 110 is completed.

Accordingly, the user of the reproduction apparatus 104 can reproduce apart of program information of the optical disc 100 wherein the part ofprogram information is not necessary to pay for reproduction to thesoftware house 110. However, succeeding program information can not bereproduced unless a title key is obtained from the software house 110 bypaying a suitable fee.

Furthermore, the above mentioned process of producing a cipher key is tosimplify the explanation, actually the cipher key is produced based on acomplex algorithm to increase its security. Numbers of the BCA digitsand the drive ID digits used in the above were examples. Number of thedrive ID digits can be reduced from 5 to 2. In case that the numbers ofthe drive ID digits is 2, the same drive ID is applied to severalreproduction apparatuses 104. However, it is still effective to preventfrom illegal utilization, since the probability to cause the same driveID is 1/100.

In the above mentioned first embodiment, the system which utilizesindividual cipher keys corresponding to individual program informationis disclosed. However, a system which utilizes individual cipher keyscorresponding to individual groups of program information can berealized. Further, it is possible to utilize either one of a BCA numberand a drive ID for producing a cipher key and a title key, although aBCA number and a drive ID are utilized in the embodiment exemplary. Incase that only a BCA number is utilized, an optical disc can bereproduced by other reproduction apparatuses once a cipher key isdisclosed to other users, that is, security is rather low. However, incase that only a drive ID is utilized, it is impossible to reproduce anoptical disc by another reproduction apparatus, that is, security ismuch higher than a method utilizing a BCA number alone.

In more specific aspect of the present invention, a title key can beutilized for all program information of an optical disc as reproductionpermitting information, though the title key is explained as informationwhich specifies one out of plural program information recorded in oneoptical disc. Further, the title key can be utilized as informationwhich specifies plural combinations of program information recorded inone optical disc. For example, when 4 bytes (equals to 32 bits) areassigned to a title key, 32 kinds of information can be specified incorresponding to individual bits. Therefore, the title key is utilizedas reproduction permitting information for plural program information.

In addition thereto, according to the present invention, a cost forreproducing program information is lowered and an optical disc will beprevented from illegal reproduction since a user just pay for specificprogram information to be reproduced not for all program informationrecorded in one optical disc. Therefore, an optical disc which containsmany program information can be manufactured in large quantities, sothat a price of one optical disc can be reduced. Furthermore, a lowerprice of an optical disc prevents a market from illegal duplication ofan optical disc.

According to the present invention, a cipher key is produced forindividual program information by utilizing both or one of IDinformation of an optical disc and a drive ID of a reproductionapparatus in conjunction with individual information ID of pluralprogram information recorded in the optical disc. Reproduction ofprogram information is permitted when a correct cipher key is inputted,so that a cost of program information for a user and a price of anoptical disc is lowered, and an optical disc is protected from illegalduplication.

[Second Embodiment]

FIG. 6 shows a flow chart of transmission process of information in areproduction apparatus of optical disc shown in FIG. 3 according to thesecond embodiment of the present invention.

FIG. 7 shows a flow chart of receiving process of a cipher key andwriting process of a cipher key to an optical disc in a reproductionapparatus of optical disc shown in FIG. 3 according to the secondembodiment of the present invention.

FIG. 8 shows a flow chart of permitting or prohibiting reproductionprocess in a reproduction apparatus of optical disc shown in FIG. 3according to the second embodiment of the present invention.

FIG. 9 shows another flow chart of permitting or prohibitingreproduction process in a reproduction apparatus of optical disc shownin FIG. 3 according to the second embodiment of the present invention.

In a second embodiment of the present invention, a cipher key isproduced from inherent information of an optical disc and a code numberwhich is assigned by a user through an operational process based on apredetermined algorithm.

In FIG. 3, a reproduction apparatus 104 is provided with a ten key padfor inputting the code number by a user. The code number, theaforementioned BCA number, and the title key which specifies at leastone preferred program information out of plural program informationrecorded in an optical disc are utilized for producing a cipher key.

When an optical disc 100 is loaded, the reproduction apparatus 104reproduces program information of the disc 100 wherein reproduction ispermitted without inputting a cipher key and displays contents of theprogram information. A user can recognize an outline or a first scene ofdesired software to be reproduced. However, a cipher key of the softwareis not known to the user. A method of obtaining the cipher key willfollow on an assumption that a software number to be reproduced is "01"and the title key is "08001".

The user or the reproduction apparatus 104 notifies followinginformation to the software house 110 by transmitting a PB (Push Button)signal (dial tone signal) through a analog telecommunication line with amodem or an ISDN (Integrated Services Digital Network) line as indicatedby an arrow 112.

(1) BCA number of the optical disc 100 in 5 digits: "00123" forinstance,

(2) Code number optionally assigned by a user: "01010" for instance,

(3) Credit card number for payment for the playing fee, and

(4) Number of the software to be reproduced in 2 digits: "01".

The cipher key which permits reproduction is, for example, defined asfollows:

Cipher key =(equals) "Title Key" -(minus) "BCA number" -(minus) "Codenumber", that is, ##EQU3## The software house 110 notifies the cipherkey "06868" to the user or the reproduction apparatus 104 by a modem ora voice answer back machine on the condition that the user pays for thesoftware number "01" of the optical disc 100 as indicated by an arrow113.

FIG. 6 is a process flow chart in the reproduction apparatus 104 whereinsuitable information is transmitted to the software house 110. In a stepS31, a disc ID is read out. In a step S32, the reproduction apparatus104 requests the user to input a code number. The user assigns the codenumber and then inputs the code number by a ten key pad which isprovided in the reproduction apparatus 104. Once the input is confirmed(step S33), a software number is requested to be inputted (step S34).When the input of the software number is confirmed (step S35), a creditcard number is requested to be inputted (step S36), then the input ofthe credit card number is confirmed (step S37). When all the requiredinformation are inputted, they are transmitted to the software house 110(step S38). The transmission process comes to an end when thetransmission is completed (step S39).

A process in the software house 110 is the same process shown in FIG. 5in the first embodiment.

FIG. 7 shows a process of writing a cipher key which is transmitted fromthe software house 110 on the optical disc 100 in the reproductionapparatus 104. When a reception of cipher key is confirmed (step S41),the cipher key is written in a predetermined area of the optical disc100 (step S42). When completion of writing the cipher key is confirmed(step S43), the process comes to an end. Therefore, the reproductionapparatus 104 also functions as a cipher key writing apparatus. Anadd-on writing area as a part of BCA area is available for abovementioned predetermined area of an optical disc wherein a cipher key iswritten. The add-on writing area of BCA area is a part of BCA areawherein a disc ID is recorded as a BCA number and the add-on writingarea is continued to or adjoined to the area wherein a BCA number isrecorded. An add-on writing area of a bar code which is continued in acircumference direction to a recording area of a disc ID in a BCA area,is provided as a continuous area. An add-on writing area of a bar codewhich is adjoined in a radius direction of the disc, is also provided asan adjoined area.

FIG. 8 is a flow chart of reproduction permitting process performed inthe reproduction apparatus 104. A cipher key which is produced in thesoftware house 110 is written on an optical disc 100 by the processexplained with reference to FIG. 7. A disc ID is read out (step S51) andthe cipher key is also read out (step S52). These information arerecorded in a BCA area and are read out as a bar code. When the presenceof cipher key is confirmed (step S53), a title key is detected (stepS54) wherein detection of the title key is to find a number which iscorresponding to a software number to be reproduced. Here, a title key"08001" which is corresponding to a software number "001", for example,is detected.

In a step S55, a code number is calculated by a following equation byutilizing the disc ID, the cipher key, and the title key:

Code number =(equals) "Title key" -(minus) "BCA number" -(minus) "cipherkey", that is, ##EQU4##

The code number calculated by the above mentioned equation is defined asa calculated code number. Entering the code number is required for theuser (step S56), hereinafter the code number is defined as an enteredcode number. In a step S57, it is judged whether the entered code numberis inputted or not. When the entered code number is inputted, it isjudged whether the entered code number agrees with the calculated codenumber or not (step S58). In the case of agreement, reproduction of thesoftware number "01" of the optical disc 100 which is corresponding tothe title key "08001" is permitted (step S59). In case that the enteredcode number does not agree with the calculated code number or the cipherkey is not detected in the step S53, reproduction is prohibited orpermitted only of a restricted area (step S60).

According to another aspect of the present invention, a title key can becalculated by an entered code number instead of judging whether anentered code number inputted by a user agrees with a code numbercalculated by an above mentioned equation. FIG. 9 is a flow chart ofjudging process of reproduction of software by calculating a title key.Explanation of the step same as those shown in FIG. 8 are omitted forsimplicity. In FIG. 9, when a presence of a cipher key is confirmed(step S53), an input of a code number is required for a user (step S56).When the input of the code number is confirmed (step S57), a title keyis calculated by a following equation (step S61):

Title key =(equals) "BCA number" +(plus) "Cipher key" +(plus) "codenumber", that is, ##EQU5## It is judged whether a title which iscorresponding to the calculated tile key is present in an optical disc100 or not (step S62). In the case of present, reproduction of anapplicable title is permitted (step S59). In case that an applicabletitle is not present or a cipher key is not detected in the step S53,reproduction is prohibited or permitted only for restricted area (stepS60).

In other word, a user of a reproduction apparatus 104 can reproduceprogram information of an optical disc 100, which is not necessary to bepaid. However, succeeding program information can not be reproducedunless a title key is obtained from the software house 110 by paying asuitable fee for the program information.

A disc ID is assigned as "00123" in the above mentioned aspect. However,considering a case of reproducing program information of other opticaldiscs, a disc ID of another optical disc is assigned as "00150". Acipher key is produced in the software house 110 as shown in FIG. 5. Incase that a disc ID, a code number, and a title key are assigned as"00150", "01010", and "08001" respectively. A cipher key of anotheroptical disc is calculated as follows:

Cipher key="title key"-"disc ID"-"code number" ##EQU6## The new cipherkey "06841" is written on another optical disc through the process shownin FIG. 7. A code number or a title key is produced from the new cipherkey. Therefore, when reproducing program information from the opticaldisc (disc ID "00150"), preferred software can be reproduced by enteringthe same code number "01010" as for the optical disc (disc ID "00123").

In the above mentioned aspect, it is explained that a produced cipherkey is written in an add-on writing area of BCA area, that is, thecipher key is written in an area which is continued to or adjoined to arecording area of a disc ID. However, it is possible to record a cipherkey in a area further innermost area of an optical recording area, thatis, in a magnetic recording area which is provided in a labeling part ofan optical disc by means of magnetic recording.

The above mentioned process of producing a cipher key is to simplify theexplanation, actually a cipher key is produced by using a complexalgorithm to increase security. Numbers of disc ID digits and codenumber digits mentioned were mere examples. It is possible to utilize analphabet, other characters, or alphanumeric figures instead of numericfigures for the code number and also possible to change the number ofcode digits. It is said that a longer code number is more preventive forillegal utilization of the code. However, too many digits make itdifficult to remember or input such code numbers. A range of one bytethrough 30 bytes is preferable for a code number.

A title key is explained as information which specifies one out ofplural program information recorded in one optical disc. However, it ispossible to utilize a title key as reproduction permitting informationfor total program information of one optical disc. Further, a title keyis possible to be utilized as information which specifies a combinationof plural program information recorded in one optical disc. When 4 bytes(equals to 32 bits) are assigned to a title key, a title key is utilizedfor reproduction permitting information for plural program information,since 32 kinds of information can be specified in accordance withrespective bits.

A disc ID is not necessary to be a BCA number itself. It is acceptablethat the BCA number is encoded in a reproduction apparatus so thatinformation of a BCA number is accurately contained. In this case, it ismore effective method to increase security of a cipher key though adecoding function is necessary to a reproduction apparatus. Areproduction apparatus is explained as an add-on information writingdevice of a cipher key in the above mentioned second embodiment.However, it is possible to provide an optional device as the add-oninformation writing device of a cipher key so that a received cipher keyis inputted into the add-on information writing device and recorded in adisc ID area as a bar code or in a magnetic recording area by means ofmagnetic recording.

Further, a cipher key which is transmitted from a software house is notnecessary to be a cipher key itself. A cipher key is acceptable to be inan encoded form, which is not recognized by a user. When writing acipher key or reading a cipher key for reproducing an optical disc, theencoded cipher key is decoded and a title key is produced. A cipher keyinformation which is additionally recorded in a disc ID recording areais acceptable to be additionally recorded as far as nonrecorded area isremaining in a disc ID recording area.

Furthermore, a code number is possible to be changed after contactingwith a software house in regard to changing a code number, if a codenumber which is assigned by a user becomes inconvenient for the user,the user may request the software house to replace such code number.

Moreover, in an optical disc provided with an magnetic recording area, acipher key information written in the magnetic recording area isrewritable. A code number can be changed also in this case aftercontacting with a software house for a change of such a code number, ifthe code number assigned by a user is inconvenient for the user. In thecase of adding information desired to be utilized when the optical discincludes many information, it is possible to add a new cipher key or toreplace a current cipher key with a new cipher key which includesprevious cipher key information. It is convenient for a user that thesame code number previously utilized is still usable.

It is possible to assign different code numbers for plural programinformation or to restrict reproduction of a combination of arbitrarytitles. One specified information which specifies at least one preferredprogram information out of plural program information recorded in anoptical disc is equal to one information which permits reproduction ofone preferred program information out of plural program informationrecorded in an optical disc and such information is reproductionrestricting information itself. Therefore, information which is utilizedas a title key is reproduction restricting information. In the case ofjust one title, that is, one program information, the information isequal to reproduction permitting information of an optical disc.

According to the present invention, as a cipher key is automaticallyproduced by utilizing a code number which is arbitrarily assigned by auser, complicated management of cipher keys is not necessary for a userand selective reproduction permission of program information is realizedby utilizing a code number which is common to several optical discs.Therefore, a user can reproduce program information more conveniently. Acost for reproducing program information and a price of an optical discis reduced so as to prevent a optical disc from illegal duplication.

[Third Embodiment]

FIG. 10 shows a flow chart of producing and writing process of a cipherkey according to a third embodiment of the present invention.

FIG. 11 shows a flow chart of reproduction process of an optical discaccording to the third embodiment of the present invention.

FIG. 12 shows a block diagram of a reproduction apparatus of opticaldisc according to the third embodiment of the present invention.

In the third embodiment of the present invention, a discriminationsentence is utilized for reproducing an optical disc instead of a cipherkey. The discrimination sentence is referred to and reproduction ofprogram information is permitted when a correct discrimination sentenceis inputted.

In FIG. 10, when a desirable software or title is available in anoptical disc (step S71), a user assigns an arbitrary discriminationsentence or a cipher sentence (step S72) and transmits thediscrimination sentence and other inherent information such as personalinformation of the user to pay for the software as well as titleinformation of the preferred software to a software supplier (softwarehouse) or an agent (step S73). The personal information includes aregistered user ID at the software house, a credit card number, and abank account number.

A cipher key is produced according to a predetermined algorithm in thesoftware house (step S74), that is, the cipher key is produced byutilizing the preferable discrimination sentence of the user wherein thecipher key is acceptable to all software which are desired by the userand the cipher key contains data such as a discrimination sentence,software which is able to be reproduced, and the personal information asrequired. The software house writes the cipher key on an optical discwhich is requested by the user in exchange for a payment of a cost orfee of utilizing the program information (step S75) wherein the cipherkey is written in a BCA (Burst Cutting Area) or a low packing densityrecording area which are explained in the first embodiment of thepresent invention. The optical disc wherein the cipher key is written isdelivered to the user and the user can play the optical disc by enteringthe discrimination sentence (step S76). Further, the cipher key can betransmitted to the user in exchange for a payment of a cost and the usercan write the cipher key on an applicable optical disc by himself.

In FIGS. 11 and 12, the cipher key is written on a low packing densityrecording area or a BCA area 122 of an optical disc 100. When theoptical disc 100 is loaded in a reproduction section 124, it is checkedwhether the cipher key is written or not by a recording discriminator128 of a reproduction control section 126 (step S81 in FIG. 11). In casethat the cipher key is not present, reproduction of the optical disc 100is prohibited or permitted to reproduce only a restricted area ofprogram information by the reproduction section 124 (step S82), andreproduced program information is outputted through an output section130.

On the other hand, when the recording discriminator 128 judges that thecipher key is present the cipher key information in the BCA area 122 isreproduced, a disc ID information, a title which is permitted to bereproduced, and personal information are read out (step S83). Then adiscrimination sentence is requested to be inputted by a discriminationsentence input requesting section 134 (step S84) wherein a content ofthe request is outputted as a sound or an image by the output section130. When a discrimination sentence is entered into the input section136 (step S85), the discrimination sentence is judged whether it agreeswith the discrimination sentence which is read out from the BCA area 122or not by a discrimination sentence judging section 132 (step S86). Inthe case of coincidence, software is reproduced wherein a title of thesoftware is permitted to reproduce in correspondence to thediscrimination sentence (step S87). However, in the case of notcoincidence, the reproduction is prohibited or restricted to reproducenonrestrictive area of program information by the reproduction section124 (step S82).

In addition thereto, according to the present invention, a cipher key isproduced from a discrimination sentence which is preferred by a user,that is, when a discrimination sentence is assumed to be a key, a keyhole of each optical disc is produced so as to fit to the key.Therefore, when reproducing program information, a user can input adiscrimination sentence instead of a cipher key.

Accordingly, following advantages are present.

(1) A discrimination sentence or a cipher sentence is arbitrarilyassigned by a user. Therefore, for example, it is possible to assign asame discrimination sentence to all optical disc which are possessed bya user, so that it is not necessary to memorize individualdiscrimination sentences of respective optical discs.

(2) When a user intends to utilize one software of an optical disc whichis recorded with plural program information such as plural gamesoftwares wherein the desired one software is not registered forutilization at a software house, a new cipher key is necessary. However,the common discrimination sentence as previously utilized can beconveniently used. In this case, although a new optical disc writtenwith a new cipher key which authorizes to utilize the new software, isnecessary, an expense of a user is rather low, as a price of an opticaldisc excluding its contents is very low. It is possible to assignindividual discrimination sentences to plural program information aswell.

(3) An optical disc is distributed at a low price, since a cost ofutilizing program information is charged to an individual programinformation itself as the same case as the "super distribution system".A user can save money so that the user just pays for preferred programinformation. Further, as an optical disc is distributed at a very lowprice, illegal duplication is hardly established as a business.Furthermore, a software house can manage about users, since an opticaldisc is supplied to a user when a cipher key is requested by the user.In addition thereto, a user can obtain a low priced optical disc andpurchase desired program information after sampling nonrestrictedprogram information of each software, so that a distribution of softwareis activated.

In more specific aspect of the present invention, this invention may bepracticed or embodied in still other ways without departing from thespirit or essential character thereof. For instance, followingvariations are possible.

(1) A cipher key which is produced by a software house can be calculatedinto a form not recognizable by a user instead of a discriminationsentence. In this case, a discrimination sentence is produced by areverse calculation when writing a cipher key in an optical disc orreading out a cipher key from an optical disc. A title which ispermitted to reproduce, personal information, and permitting level ofreproduction can also be processed by calculation and be recorded in alow packing density recording area or BCA area so that security can bemore increased.

(2) A cipher key can be written in a low packing density recording areausually only one time. In case that a discrimination sentence assignedby a user is necessary to be changed, a new optical disc must beprovided. However, in consideration of an optical disc supplied at avery low price, it is convenient for a user and a software house tosupply a new optical disc written with a new cipher key which is basedon a new discrimination sentence at a certain fee or free of charge onthe basis of taking back an old optical disc wherein a former cipher keyis written, once the user pays for the software of the old optical disc.

(3) In the above mentioned third embodiment, a part of programinformation recorded in an optical disc is permitted to be reproduced bya discrimination sentence. However, it may be allowed to permitreproduction of all the program information in the optical disc.

(4) One discrimination sentence is provided for one optical disc in theabove mentioned third embodiment. However, it is possible to containseveral discrimination sentences in one cipher key or to assignindividual discrimination sentences in correspondence to plural programinformation in an optical disc. In this case, it can be practiced torestrict reproduction of combinations of arbitrary titles, and it iseffective to share one optical disc with several users. For example, incase that game software "GA", "GB", "GC", "GD", and so on are recordedin one optical disc, a user "A" utilizes the game software "GC" by adiscrimination sentence "a" and another user "B" utilizes the gamesoftware "GA", "GB", and "GC" by a discrimination sentence "b". In thiscase, if 4 bytes (equals to 32 bits) are assigned to a title key whichspecifies software being permitted to utilize, for instance, 32 titlesof software can be specified totally so that each bit can correspond toone title whether the title is permitted to utilize or not.

(5) Characters such as numeric figures, letters, or symbols may beutilized for a discrimination sentence. A discrimination sentence ispreferable to be ranged one byte to 30 bytes in code digits, a name, ora short sentence.

(6) In case of DVD (Digital Video Disc), a BCA (Burst Cutting Area) ispreferable to a low packing density recording area.

In addition thereto, according to the present invention, a cipher key isproduced by a discrimination sentence preferred by a user so thatmanagement of a cipher key is simplified and handling of a cipher key isimproved in conjunction with preventing program information from illegalutilization and illegal duplication.

What is claimed is:
 1. A cipher key producing method comprising:a stepof reading a first proper information out from a recording mediumwherein the first proper information is inherent to the recording mediumand discriminates the recording medium recorded with program informationfrom other recording mediums; a step of reading out a second properinformation inherent to a reproduction apparatus from a memory means ofthe reproduction apparatus wherein the second proper informationdiscriminates the reproduction apparatus from other reproductionapparatuses for reading out the program information of the recordingmedium; a step of reading out from the recording medium a specificinformation which specifies at least one preferred information of theprogram information; and a step of producing at least one cipher key forreading out said one preferred program wherein the cipher key isproduced through a calculation process according to a predeterminedalgorithm by using said first and second proper information and thespecific information.
 2. A cipher key producing method comprising:a stepof reading a proper information out from a recording medium wherein theproper information is inherent to the recording medium and discriminatesthe recording medium recorded with program information from otherrecording medium; a step of reading out from the recording medium aspecific information which specifies at least one preferred informationof the program information; and a step of producing at least one cipherkey for reading out said one preferred information wherein the cipherkey is produced through a calculation process according to apredetermined algorithm by using said proper information and thespecific information.
 3. A cipher key producing method comprising:a stepof reading a proper information out from a recording medium wherein theproper information is inherent to the recording medium and discriminatesthe recording medium recorded with program information from otherrecording mediums; a step of reading out from the recording medium aspecific information which specifies at least one preferred informationof the program information; and a step of producing at least one cipherkey for reading out said one preferred information wherein the cipherkey is produced through a calculation process according to apredetermined algorithm by using said proper information.
 4. A cipherkey producing method comprising:a step of reading out a properinformation inherent to a reproduction apparatus from a memory means ofthe reproduction apparatus wherein the proper information discriminatesthe reproduction apparatus from other reproduction apparatuses forreading out the program information of the recording medium; a step ofreading out from the recording medium a specific information whichspecifies at least one preferred information of the program information;and a step of producing at least one cipher key for reading out said onepreferred information wherein the cipher key is produced through acalculation process according to a predetermined algorithm by using saidproper information and the specific information.
 5. A cipher keyproducing method comprising:a step of reading a proper information outfrom a recording medium wherein the proper information is inherent tothe recording medium and discriminates the recording medium recordedwith program information from other recording mediums; a step ofassigning a code number by a user; a step of receiving the code numberfrom the user; and a step of producing at least one cipher key forreading a program information out from the recording medium wherein thecipher key is produced through a calculation process according to apredetermined algorithm by using said proper information and the codenumber.
 6. A cipher key producing method comprising:a step of reading aproper information out from a recording medium wherein the properinformation is inherent to the recording medium and discriminates therecording medium recorded with program information from other recordingmediums; a step of assigning a code number by a user; a step ofreceiving the code number from the user; a step of reading out from therecording medium a specific information which specifies at least onepreferred information of the program information assigned by the user;and a step of producing a cipher key for reading out said one preferredinformation wherein the cipher key is produced through a calculationprocess according to a predetermined algorithm by using said properinformation, and the code number, and the specific information.
 7. Acipher key producing method, wherein the cipher key is recorded in otherarea than a main information area of an optical disc by a request of auser and utilized for reproducing main information comprising:a step ofassigning a discrimination sentence which is utilized for reproducingmain information recorded in an optical disc by the user; a step ofselecting a specific information which specifies at least one preferredinformation of the main information by the user; a step of transmittingsaid discrimination sentence and the specific information to a softwarehouse; and a step of producing a cipher key for reading out said onepreferred information wherein the cipher key is produced through acalculation process according to a predetermined algorithm by using saiddiscrimination sentence and the specific information.